Variable speed transmission



1933- J. H. HOLLESTELLE 2,136,437

VARIABLE SPEED TRANSMISSION Original Filed March 14, 1931 3 Sheets-Sheet 1 Nov. 15, 1938. J. H. HOLLESTELLE 2,136,437

VARIABLE SPEED TRANSMISS ION Original Filed March 14, 1931 5 Sheets-Sheet 2 5 .50 E fi J L 3/ 13 5; g7 59 g 3952 8 Z4 a? 4 I 25 07 5 g; 4/ 16 a 17 f j i r g a? g g 6/ 4 5 ll/11111111,

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J. H. HOLLESTELLE VARIABLE SPEED TRANSMISSION Original Filed March 14, 1931 3 Sheets-Sheet 3 Patented Nov. 15, 1938 PATENT OFFICE VARIABLE SPEED rasnsmssron Jan H. Hollestelle, Evanston, Ill., assignor, by mesne assignments, to U. S. Electrical Motors, Inc., a corporation ofCalifornia Application March 14, 1931, Serial No. 522,591 Renewed September 29, 1937 12 Claims.

This invention relates to variable speed transmissions of the cone-pulley type. Variable speed transmissions of this type generally consist of a pair of pulleys and a connecting belt, each pulley consisting of a pair of oppositely facing cones (i. e. tapered sections or disks) keyed or splined on a shaft, with one of the cones slidabie toward and from the other, thus creating a V-shaped groove which is narrowed or widened by bodily shifting one of the cones toward or from the other. The belt that connects the two pulleys has beveled or tapered edges which frictionally engage with the faces of the two cones forming each pulley, and means are provided for simultaneously expanding one pulley and contracting the other, whereby the effective radius of one pulley is lengthened and that of the other is correspondingly shortened.

. Heretofore, in variable speed transmissions of this type, in order to obtain a substantial increase or reduction of speed it has been necessary to either employ a very wide belt, or to make the inclined faces of the cone sections of the pulley very steep. The main trouble with a 26 wide belt is the tendency to flap edge-ways, or to climb the sides of the pulleys. Also, where a wide belt is employed the latter has to be so made as to possess a high degree of transverse of the cam.

One object of my present invention is to provide an improved variable speed transmission of the type referred to which will permit the use of a narrow belt and also a very long belt be 40 tween pulleys a long distance apart. To accomplish this, I construct the laterally movable member of the pulley in a plurality of concentric ring-shaped inter-nested sections, with means for locking them together and means for shifting them successively toward the opposed member of the pulley and automatically locking them in such shifted position, whereby said sections may be successively brought into cooperation with the connector belt.

. Other objects of the invention are, .to provide an improvedmechanism for moving the laterally shiftable cone toward and from its mating cone,

to provide an improved mechanismwhereby the shiftable cones of the two pulleys are simultane- 65 ously moved in opposite directions relatively to their mating cones from a single operating handle or lever when varying the speed, to provide an improved means for locking stationary the two cams through which the shifting is eifected,

to provide novel and eflicient automatic locking 5 means between the annular sections of the laterally shiftable cone, and to provide improved means for locking each pulley to its shaft.

Still other objects and attendant advantages of the invention will become apparent to persons 10 skilled in the art as the same becomes better understood by reference to the following detailed description, taken .in connection with the ac.- companying drawings in which I have illustrated a practical and workable embodiment of the in- 15 vention, and wherein- Fig. 1 is a side elevational view of the apparatus.

Fig. 2 is a top plan view.

Fig. 3 is an enlarged sectional view through 20 one of the pulleys and its mounting means, showing the annular sections of the shiftable cone in outer position and the drive belt at the inner periphery.

Fig. 4 is a view similar to Fig. 3 showing the 25 annular sections of the shiftable cone in their innermost position, with the drive belt at the outer periphery.

Fig. 5 is a transverse section taken on the line 5-5 of Fig. 3. 30 Fig. 6 is an enlarged sectional detail showing a modified construction of automatic locking pin.

Referring to Figs. 1 and 2 of the drawings,

A and B designate a pair of parallel shafts, either C and D, respectively. Inasmuch as these expanding pulleys and their operating means are identical, except that they are preferably rela- 40 tively inverted endwise as shown in Fig. 2, a description of one will suffice for both.

Referring to Figs. 3 and 4, l0 designates one of the cone-shaped sections of the pulley formed with a hub ll. The working face of the other 5 cone-shaped section of the pulley is made up of a plurality of concentric inter-nested rings, of which the outermost is designated by II. Integral or otherwise fast with the ring [2 is a hollow cup-shaped web l3 and a long sleeve-like 50 hub lithatis splined on the shaft by a key l5 so as to be slidable lengthwise of the shaft. The

,hub ll of the pulley section III is mounted on the sleeve II. The sleeve I4 is formed with longitudinal slots-l6 and I1, and the hub I I is locked to the shaft by a group of pins l3, Fig. 5, that extend through the slots I6 and through spacing sleeves I3 that prevent clamping of the hub II on the hub i4 and thus serve to maintain an easy sliding fit for the hub l4 through the hub Concentrically nested within the outer ring l2 and its web l3 are a group of independently shiftable rings 23, 2| and 22, the inner faces of which are tapered, as clearly shown in Fig. 3, to conform to the taper of the inner face of ring I2, so that in the outermost position shown in Fig. 3'the tapered faces of the rings I2, 23, 2| and 22 form a continuous tapered or conical surface matching that of the opposed pulley section l3.

The ring sections 23, 2| and 22 are equipped with spring actuated locking pins which cooperate with recesses or notches in the ring sections 2|, 22 and I2, respectively, to normally maintain the ring sections in their outermost positions shown in Fig. 3. More specifically describing these features, 23 designates a locking pin mounted in a socket 24 in the ring 23 and normally thrust outwardly by a spring 25. 26 designates a similar locking pin mounted in a socket 21 in the ring 2| and normally thrust outwardly by a spring 23; and 29 designates a similar looking pin mounted in a recess 33 in the ring 22 and normally thrust outwardly by a spring 3|. The locking pin 23 has a beveled head 32 that enters a correspondingly shaped socket 33 in the ring 2|; the locking pin 26 has a beveled head 34 that enters a correspondingly shaped socket 35 in the ring 22; and the locking pin 23 has a beveled head 36 that enters a correspondingly shaped socket-31 in the ring'l2. As the outer ring I2 is moved inwardly, by means hereinafter described, the three inner-rings 22, 2| and 23 move inwardly with it until the lower end of the locking pin 23 registers with a hole 33 in the shaft A, whereupon the socket 33 of the ring 2|, acting upon the beveled head 32 of the pin, cams the lower end of the pin into' the hole 33, as shown in Fig. 4. Under a further inward movement of the rings I2, 22 and 2|, the lower end of locking pin 26 is forced into'asimilar hole 39 in the outer s|de of ring 23 by the camming action of the recess 35 on the head 34. Under a still further inward movement of the rings 'l2 and 22, the lower end of locking pin 29 is forced into a similar hole 43 in the ring 2| under the camming action of the recess 31 on the head 36, and under a still further inward movement of the ring l2, the inner periphery of the, latter approaches and contacts with the tapered face of the cone section I3, all as clearly shown in Fig. 4. Manifestly in this position of the parts the three rings 23, 2| and 22 are all locked to each other, and this is also the case in the expanded position of the same rings shown in Fig. 3. It may here be remarked that in practice the several locking pins 23, 26 and 29 are disposed in different radial planes, but, of course, the pin 26 is in the same radial plane with its cooperating hole 33, and the pin 29 is in the same radial plane with its cooperating hole 43; and while I have illustrated but a single series of locking pins, there may be, of course, several series of locking pins spaced around the axis of the shaft.

Describing next the mechanism for effecting the expanding and contracting movements of the two pulleys, fitted within an annular groove 4| of the hub H is a ring 42, to which ring is at-- tached, as by screws 43, the inner end of a hollow cylinder or drum 44, the outer closed end of said drum being mounted on the shaft. In

the surface of said drum are cam slots 45. The two drums 44 are maintained stationary by any suitable means, that herein shown consisting of a steadying bar 46 (Figs. 1 and 2) equipped at each end with a fork 41 that, as shown in Fig. 3 straddles a pair of ring segments 48 (Fig. 5) riveted or otherwise secured to the inner end of the cylinder 44 and is keyed to said segments by set-screws 49'.

Referring to Figs. 1, 2 and 3, 53 designates a bail, one arm of which terminates in a hub 5l encircling the'shaft A and key i5, while the other arm terminates in a ring 52 having a bearing on the cylinder 44. The ring 52 is equipped with a pair of cam followers in the form of inwardly extending pins 53 that enter a collar 54 inside the cylinder 44, said collar being lockedto the long hub H by an annular rib 55 that lies within an annular groove 56 in the hub I4. The two pins 53 extend through the cam grooves 45 of the cylinder 44. The transversemember of the bail 53 is equipped with' a handle 51. On the hub 5| of the bail 53 are oppositely extending arms 53 (Figs. 1 and 2) that are connected by links 53 with corresponding arms 63 on the ring 52 of the other cylinder 44, as clearly shown in Fig. 2. l

Extending between the two pulleys is the connector belt 6| formed with tapered edges fitting the tapered faces of the two cone sections of each pulley.

Briefly describing the operation, assume that the shaft A is the driving shaft and the shaft B the driven shaft, with the belt 6| in the position shown in Figs. 1, 2 and 3. In this position of the parts it will be observed that the driving pulley on shaft A is fully expanded, and the driven pulley on shaft B is fully contracted. If, now, it is desired to increase the speed of the driven shaft B, the ball 53 is swung, and the engagement of the pins 53 with the cam slots 45 of the two drums 44 effects simultaneous endwise movements of the hubs l4 of the two shiftable pulley members. This effects an inward movement of the interlocked pulley sections 23, 2|, 22 and I2 on the shaft A and a simultaneous outward movement of the pulley section |2 on the shaft B. This causes one loop of the belt to move outwardly into engagement with the pulley section 2| on shaft A and the opposite loop of the belt to simultaneously move inwardly into engagement with the pulley section 22 on shaft B. A further swing of the ball 53 in the same direction effects a further inward movement of sections 2|, 22 and i2 on shaft A and an outward movement of section 22 on shaft B. This causes one loop of the belt to move further outwardly into engagement with section 22 on shaft A and the other loop to move further inwardly into engagement with section 2| on shaft B. At this point, in the construction shown, the driven shaft B rotates at a higher speed than the driving shaft A; and the maximum speed of the driven shaft B may be effected by a further swing of the ball 53 in the same direction, causing one loop of the belt to be shifted into driven engagement with the outer section H on shaft A and the other loop into driving engagement with the inner section 23 on shaft B. Manifestly, by then swinging the ball 53 backwardly or in the reverse direction, the speed of the driven shaft B is stepped down.

During these operations, as soon as the inner ring 23 reaches the position shown in Fig. 4. the locking pin 23 is cammed down into the hole 33 by the inclined rear side of the recess 33 in I respective locking pins.

Kid

the next outlying ring it. In the same way, as the rings ii, 22 and it are moved inwardly, the rings ti and 22 are successively locked by their The outer ring i2 is held locked in innermost position bythe engagement of the pins 53 with the cam grooves it being understood that in practice thebail fill will be equipped with a suitable segment rack and locking dog (not shown) for holding it in any shifted position. By reference to Fig. 4it will be observed that as each ring is shifted inwardly, it automatically holds the locking pin of the next inner ring in locking position; and as the rings are successively shifted outwardly, the heads of the locking pins, under the thrust of their respective springs, snap up into the locking recesses in the next outer rings, and are held there by the next inner rings and the shaft which block unlocking movement of the locking pins, as shown in Mg. 3.

In Fig. 6 I have illustrated a modification of the locking pin which has some advantages over the simple one-piece structure of locking pin shown in Figs. 3 and 4. Here the pin head and stem are made in two pieces 62 and iii, respectively, the

head ti slidably fitting the socket fi l and beingv urged outwardly by a coil spring he. The upper end of the stem t3 has a sliding fit'in a socket M in the head 62 and also a sliding fit at its lower end in a hole iii in the bottom wall of the socket fit. A light thrust spring '68 confined between the top of the stem 63 and the end wall of the socket t6 urges the stem t3 downwardly. The head t2 and stem t3 are connected by a tie rod fit, the head it of which has a limited play in a socket ill in the lower end of the stem if. The rear edge of the locking hole 39 underlying the pin is preferably formed with an inclined approach if for the descent of the head it! of'the tie rod M as the pin moves into register with the hole 359. As soon as the pin registers with the hole til, the spring 68 instantly forces it fully into engagement with the hole 39, and this irrespective of wear on the head ti. It will thus be seen that the function of the larger spring M is to withdraw the pin from the hole of the adjacent inner section of the pulley, or shaft, as

the pulley expands and to force its head into the adjacent outer section of the pulley-and hold it there until the pulley is again contracted, while the smaller spring 68 forces the pin into locking engagement with the underlying hole and compensates for wear.

From the foregoing it will be apparent that the device of the present invention renders practical the use of a narrow belt connector for they two pulleys and at the same time makes possible 9. wide variation in speed between the driving and driven pulleys, and also avoids such a,

vantages secured by the invention. Hence, I do,

not limit the invention to the particular embodiment shown, but reserve all such variations, modifications and mechanical equivalents as fall within the spirit and purview of the appended claims.

I claim: l. in a variable speed transmission of the type described, the combination of a shaft, a pair of pulley sections on sail shaft formed with opposed tapered surfaces, one of said pulley sections comprising a group of concentric parts, means for locking the outermost part of said group against rotation relatively to said shaft, means for shifting said outermost part toward and from the opposed tapered surface of the other pulley section; all of said parts except the innermost having locking recesses in their inner peripheries, and said shaft and certain of said parts having locking holes in their outer peripheries, and outwardly spring pressed pins slidably mounted in all of said parts except the outermost, said pins at their outer ends engaging with said recesses to lock said parts together at the limits of their outward movements, and said pins at their inner ends engaging with said holes to lock said parts together at the limits of their inward movements.

2. A specific form of claim 1, wherein the outer ends of said pins have beveled engagement with their respective recesses whereby, as each part is moved inwardly, a locking pin carried thereby is forced inwardly into locking engagement with, the hole in the next inner part or shaft.

3. In a variable speed transmission mechanism, the combination of parallel shafts, pulleys mounted on the respective shafts, each of said pulleys comprising a pair of mating pulley sections having opposed tapered belt-engaging faces, one section of each pulley being fast on its shaft, and the other section being keyed to and shiftable lengthwise of the shaft, a belt connecting said pulleys, single-grooved oscillatable cams mounted on each of said shafts and connected to said fixed sections, and manually operable means connecting said cams with said shiftable sections effective to simultaneously move said shiftable sectionsto equal extents in opposite directions relatively to their respective mating sections.

d. In a variable speed transmissionmechanism, the combination of parallel shafts, pulleys mounted on the respective shafts, each of said pulleys comprising a pair of mating pulley sections having opposed tapered belt-engaging faces, one section of each pulley being fast on said shaft, the other section being splined to and shiftable length-Wise of the shaft, one of the sections of each pulley comprising a plurality of shiftable concentrically nested parts, means for locking each part with the next adjacent part, a belt connecting said pulleys, single grooved oscillatable cam drums mounted on the respective shafts, a steadying bar connecting said drums together, and manually operable means connecting said drums with said shiftable sections effective to simultaneously move said shiftable sections to equal amounts in opposite directions relatively to their respective mating sections.

5. In a variable speed transmission mechanism, the combination of parallel shafts, pulleys mounted on the respective shafts, each of said pulleys comprising a pair of mating pulley sections having opposed tapered belt-engaging faces, one section of each pulley being fast on its shaft and the other section having a hub splined to and'slidable lengthwise of the shaft, a stationary single-grooved cam mounted on said shaft, rings swiveledon the respective pulley hubs of. said shiftable pulley sections, cam followers carried by said rings, and manually operable means for simultaneously rotating said rings.

6. A specific form claim 5, wherein the slidable hub of each laterally shiftable pulley section is longitudinally slotted, and the hub of its mating section is recessed thereon and keyed to the shatt by radial pins extending through said longitudinal slots.

"I. In a pulley structure having outer, intermediate and inner relatively slidable sections, a locking pin structure for locking'said intermediate section. to either of said outer and inner sections comprising a chambered head slidably mounted in said intermediate section, a stem at one end telescopingly engaged with the chamber of said head, a spring urging said head toward said outer section, a spring urging said stem toward said inner section, and a lost motion connection between said head and stem.

8. In a pulley structure having outer, intermediate and inner relatively slidable sections, a locking pin structure for locking said intermediate section to either of said outer and inner sections comprising a chambered head slidably mounted in said intermediate section, a stem at one end telescopingly engaged with the chamber of said head, a thrust spring encircling said stem and urging said head toward said outer section, a thrust spring in said chamber urging said stem toward said inner section, and a lost motion connection between said head and stem comprising a tie-rod extending lengthwise through said stem and at its outer end connected to said head and at its inner end formed with a head having movement limiting engagement with the inner end of said stem.

9. In an adjustable diameter pulley structure, a pair of sections having opposed inclined belt engaging faces, forming by relative axial adjustment, variable effective diameters, a shaft upon which said pulley sections are supported, one of said pulley sections having a plurality of concentric parts,' means for moving the outermost part, a radial pin carried by the innermost part and adapted to be received in a recess in the shaft, and means operated by relative axial movement of the next concentric part for causing said pin to be moved out oi! the recess.

1 In an adjustable diameter pulley structure, a pair of sections having opposed inclined belt engaging faces, forming by relative axial adjustment, variable effective diameters, a shaft upon which said pulley sections are supported, one of said pulley sections having a plurality of concentric parts, means for moving the outermost part, and a radial pin carried by the innermost part and adapted to be received in a recess in the shaft, said recess being so located that the said innermost part locks in its nearest position to the opposed pulley section.

11. In an adjustable diameter pulley structure, a pair of sections having opposed inclined belt engaging faces, forming by relative axial adjustment, variable effective diameters, a shaft upon which said pulley sections are supported, one of said pulley sections having a plurality of concentric parts, means for moving the outermost part, radial pins 101' locking successive parts together, and means responsive to the arrival of the parts in succession to their nearest positions to the opposed pulley sections for urging the pins in succesion to locking positions.

12. In an adjustable diameter pulley structure, apair of sections having opposed inclined belt engaging faces, forming by relative axial adjustment, variable effective diameters, a shaft upon which said pulley sections are supported, one of said pulley sections having a plurality of concentric parts, a drum concentric with the pulley structure and connected to the other to permit relative rotation of said other section, said drum having a groove, and means guided by the groove for moving the said one of said pulley sections in an axial direction.

JAN H. HOLLES'I'ELLE.

3E pulley section to restrain its axial motion and 

